1. Field of the Invention
The present invention relates to a communication apparatus, a communication method and a communication program for carrying out communication with the use of an IPv6 address.
2. The Description of the Related Art
They said that the problem concerning a depletion of IP addresses will be solved by means of application of IPv6. Accordingly, it is expected that many apparatuses will be connected to a communication network from now. Along therewith, a work amount required for network management may increase accordingly. A work amount will increase much if IP addresses are set one by one for respective ones of the very many communication apparatuses. In order to solve this problem, a scheme of automatic connection thanks to a so-called plug-and-play function is prevailing.
One of two methods, i.e., a state-full method for preparing IP addresses in an address pool and a stateless method (i.e., “stateless address autoconfiguration”) for not requiring such an address pool, may be applied for such a plug-and-play function for setting the addresses. As the state-full method, a system using DHCP (Dynamic Host Configuration Protocol) is applied. On the other hand, in the stateless method, which is prescribed in a standard for IPv6, a router advertisement including network prefix information (i.e., network addresses and so forth) is issued for a segment of a network. Each network apparatus then automatically generates an IP address with the use of the network prefix thus obtained and the interface identifier of its own.
With the use of such a plug-and-play function, many apparatuses can be connected to a communication network without requiring an extra work load by a network manager. In particular, when the use of IPv6 prevails, it is expected that communication networks operating with the use of such stateless address autoconfiguration plug-and-play function increases, since the operation becomes easier.
Thus, in IPv6, an address generated by stateless address autoconfiguration can be automatically set based on network information submitted by a router.